保护地球，探索宇宙，发现文明
2022年5月21日 Planetary Nebula Abell 7 Image Credit & Copyright: Donald Waid, Ron Dilulio Explanation: Very faint planetary nebula Abell 7 is some 1,800 light-years distant, just south of Orion in planet Earth’s skies in the constellation Lepus, The Hare. Surrounded by Milky Way stars and near the line-of-sight to distant background galaxies, its gen...
2022年3月25日 The Medusa Nebula Image Credit & Copyright: Damien Cannane Explanation: Braided and serpentine filaments of glowing gas suggest this nebula’s popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula ...
2021年11月07日 The Cat’s Eye Nebula in Optical and X-ray Image Credit: NASA, ESA, Hubble Legacy Archive; Chandra X-ray Obs.; Processing & Copyright: Rudy Pohl Explanation: To some it looks like a cat’s eye. To others, perhaps like a giant cosmic conch shell. It is actually one of brightest and most highly detailed planetary nebula known, compose...
2021年10月14日 NGC 7293: The Helix Nebula Image Credit & Copyright: Ignacio Diaz Bobillo Explanation: A mere seven hundred light years from Earth, toward the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final ...
2021年7月12日 M27: The Dumbbell Nebula Image Credit & Copyright: Bray Falls & Keith Quattrocchi Explanation: What will become of our Sun? The first hint of our Sun’s future was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier’s...
2021年04月25日 Planetary Nebula Mz3: The Ant Nebula Image Credit: R. Sahai (JPL) et al., Hubble Heritage Team, ESA, NASA Explanation: Why isn’t this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not r...
2021年03月26日 The Medusa Nebula Image Credit & Copyright: Josep Drudis Explanation: Braided and serpentine filaments of glowing gas suggest this nebula’s popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula i...
2020年10月16日 Planetary Nebula Abell 78 Image Credit & Copyright: Bernhard Hubl Explanation: Planetary nebula Abell 78 stands out in this colorful telescopic skyscape. In fact the colors of the spiky Milky Way stars depend on their surface temperatures, both cooler (yellowish) and hotter (bluish) than the Sun. But Abell 78 shines by the characteristic emi...
2020年9月13日 M2-9: Wings of a Butterfly Nebula Image Credit: Hubble Legacy Archive, NASA, ESA – Processing: Judy Schmidt Explanation: Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured here, the stars transform the...
2020年8月23日 The Helix Nebula from Blanco and Hubble Image Credit: C. R. O’Dell, (Vanderbilt) et al. ESA, NOAO, NASA Explanation: How did a star create the Helix nebula? The shapes of planetary nebula like the Helix are important because they likely hold clues to how stars like the Sun end their lives. Observations by the orbiting Hubble Space Telescope ...